Chapter 8 Long Term Challenges
Chapter 1 focuses on the Wastewater Utility’s mission (Reliable utility service is provided at the lowest reasonable cost, consistent with the City’s aims of environmental stewardship, social equity, economic development and the protection of public health.) and how the mission relates to the City’s overall Comprehensive Plan. This chapter focuses on the Utility’s long term challenges.
The Wastewater Utility faces numerous challenges in providing wastewater service consistent with its mission. The 2013 Wastewater Management Plan identified nine key challenges: (1) existing infrastructure, (2) converting septic systems, also known as onsite sewage systems (OSS), to the City’s wastewater system, (3) extending sewer infrastructure to new development, (4) sea level rise, (5) use of drinking water resources, (6) use of energy resources, (7) coordination with LOTT Clean Water Alliance (LOTT), (8) equitable and predictable rates and fees, and (9) public education and involvement. Since 2013, utility staff have taken major steps to address these nine challenges; however, they along with others remain to be addressed in this and future Wastewater Utility plans.
This chapter discusses the following eight challenges that the Wastewater Utility now faces and will continue to face for the foreseeable future:
1. Aging Infrastructure
2. Onsite Sewage Systems (OSS)
3. Extending Sewer Infrastructure to New Development
4. Climate Change
5. Equitable and Predictable Rates and Fees
6. STEP Systems
7. Inflow and Infiltration
8. Fats, Oils and Grease (FOG)
These challenges provide a basis for Chapter 9, which details how utility staff intend to respond to these Challenges through the goals, objectives and strategies that are the focus of this Plan.
8.1 Aging Infrastructure
Aging and maintenance-intensive infrastructure poses risks to public health and water quality. Understanding the condition of the Utility's infrastructure assists with replacement and maintenance decisions and is referred to as "asset management". Effective operations and maintenance are critical to the wastewater system.
The Utility's infrastructure is aging. This challenge focuses on the Utility's aging pipes, maintenance holes and lift stations. How to adequately fund the replacement of aging infrastructure is a key concern for the Utility. Implementing asset management tools will assist the Utility to make informed infrastructure maintenance and replacement decisions, thereby leading to lower life cycle costs. Information related to financing the Utility's operation and maintenance programs and capital projects can be found in Chapter 11.
Deteriorating Pipes and Maintenance holes
Olympia's wastewater system includes about 187 miles of gravity sewer pipes and over 4,000 maintenance holes. More than 30% (by total length) of Olympia's sewer pipes are more than 50 years old and made of either concrete or vitreous clay pipe. These types of pipe are most susceptible to structural issues such as cracking/breaking and corrosion, which leads to infiltration of groundwater and/or eventual pipe failure if not corrected.
Aging brick and concrete maintenance holes are also susceptible to corrosion and structural failure unless repaired or replaced in a timely manner.
Given the extensive and aging wastewater system, understanding the operational and structural integrity of pipes and maintenance holes is critical to environmental stewardship and public health as well as long-term financial planning. Effective operations and maintenance of these systems is essential. Understanding the systems through asset management techniques is necessary for improved cost effectiveness.
The gravity sewer pipe condition rating program, set up in 2006 to identify and characterize both structural and operational deficiencies of all gravity sewer pipes in the system, has reached the end of its first round of inspections. Under the program, pipes are inspected and assigned a numeric value corresponding to their condition and potential life expectancy. The pipes are being re-inspected on a schedule based on material and pipe condition. The older (higher probability of failure) and/or more critical (higher consequence of failure) a pipe is, the more frequent a video inspection will occur. The schedule varies from yearly to once every twenty-five years.
Structural and operational deficiencies identified are either corrected by City maintenance activities or capital facility projects, using trenchless technologies whenever feasible. Completion of the first round of pipe inspections in 2015 was an important accomplishment of the wastewater program.
This condition rating system supports the identification of pipes needing repairs or replacement. In doing so, the rating system will help determine financial and resource needs.
The maintenance hole condition rating program, started in 2008, involves rating maintenance holes based on condition of individual components such as the barrel, ladder, ring and cover. As of December 2018, 75% of maintenance holes have been inspected.
Lift Stations
The Wastewater Utility owns 31 lift stations. Associated with these lift stations are 9.5 miles of force mains (pressurized pipes), ranging from 4-30 inches in diameter.
The Utility has a robust capital facility program to replace or upgrade older lift stations. Concerns regarding structural integrity and capacity of these older lift stations and force mains are similar to those described above. Failure of a lift station to operate as designed, or the absence of a generator during a prolonged power failure, may result in a sewer overflow. This risk is increased if multiple lift stations are affected by a widespread power outage.
Asset management goals and strategies of the Plan also address the condition of existing lift stations using criteria similar to the gravity sewer pipe condition rating program described above. Repairs and/or replacement of elements of these lift stations, including the installation of an onsite generator at those locations without one, are scheduled as part of the capital facilities program described in Chapter 10.
8.2 Onsite Sewage Systems (OSS)
Although progress has been made on the removal of OSS located within the city limits and the urban growth area in recent years, OSS in urban areas continue to threaten water quality and public health, particularly in northeast and southeast Olympia.
The presence of approximately 4,225 OSS in Olympia and its urban growth area (UGA) creates potential long-term risks to the environment through groundwater, surface water and soil contamination. In addition, there is the public health risk of direct contact between people and sewage (also known as wastewater) from failed OSS. OSS typically have a life expectancy of 20-30 years but are often used longer. In an urban setting, OSS are best used as an interim form of wastewater treatment until municipal sewer service is available.
One environmental impact of OSS is the increasing discharge of nitrates to surface and ground waters. Nitrates, which are generated by OSS as waste decomposes, are increasingly observed in groundwater and surface water, including the City's drinking water supply wells in Southeast Olympia. In some cases, the concentration of nitrates threatens the viability of both private and public drinking water supplies. See Chapter 4 for further discussion on the challenges associated with permitting and converting OSS to sewer service.
Converting OSS to sewer service helps reduce public health risks and maintain water quality in surface and ground water. However, the conversion of OSS to sewer service is costly, and therefore challenging, for both residents and the Utility. The cost of converting from an OSS to the public sewer system can range from $7,000 to over $50,000.
Existing and new programs to facilitate and fund conversions of OSS to sewer service are discussed in Chapter 9. These include the Septic to Sewer Program, a connection fee payment plan, capital projects to extend sewer infrastructure into already developed areas, and technical assistance. Coordination with Thurston County and LOTT on these and other OSS-related activities will continue under this Plan.
A related challenge is extending sewer infrastructure to serve new development in both the City and the UGA fast enough to prevent the installation of yet more OSS. While the City does not have an extension program in place for small developments or single-lot infill homes, utility staff intend to address this within the framework of the Objectives identified in Chapter 9.
8.3 Extending Sewer Infrastructure to New Development
Planned development in Olympia and its UGA requires planning for and financing sewer infrastructure extensions effectively and equitably.
Municipal sewer service is the preferred method of wastewater management in increasingly urban communities such as Olympia. Compared to OSS, the various methods of conveying wastewater to a regional treatment facility (e.g., gravity sewer pipes, lift stations, STEP systems, grinder pumps) reduce the potential for public and environmental health risks. However, wastewater goals and policies may conflict with other City goals (e.g. promoting infill development) as well as residents' financial interests.
Sewer service relies upon comprehensive and integrated pipe systems. Local topography often creates conditions that require regional lift stations or other pressurized methods of conveyance. Where lift stations are necessary, both construction and maintenance costs are high. To minimize the number of lift stations, infrastructure planning needs to foresee development patterns and require lift stations in optimum locations.
The development of a comprehensive, cost-effective wastewater system over time requires careful and consistent planning and implementation. Coordination between various City departments, developers, and individual property owners is essential. Providing comprehensive sewer service equitably and efficiently will remain a key utility priority and challenge.
In some cases, the City and/or the Utility may choose to take a more active role in financing the infrastructure needed to support new development. Two ways this can be accomplished is by extending sewer infrastructure associated with major roadway construction projects and establishing developer reimbursement agreements, also known as latecomer agreements. In addition, the City provides technical assistance and reviews projects during several phases of project development.
8.4 Climate Change
Changing climate in the Pacific Northwest likely will result in increased rainfall and rising seas. Increased rainfall and associated flooding could result in increased flows into downtown's combined storm/sewer system. Approximately five sewer pump stations could be impacted by rising seas. Early adaptation to higher sea levels may allow for continued reliability and lowest reasonable costs. Efforts made by the Wastewater Utility such as reducing its energy use and promoting water conservation activities could assist the community in its efforts to mitigate climate change
The City currently experiences occasional flooding in the downtown area due to extreme high tides. Because of relatively low ground levels in some developed areas of the City, and multiple open stormwater outfalls discharging to Budd Inlet, flooding will become more of a problem as the mean sea level rises. As streets and parking lots flood, water can enter downtown's combined stormwater and wastewater pipe system. These flood flows could exceed the capacity of the pipes and Budd Inlet Treatment Plant, creating public and environmental health concerns as well as affecting local businesses and the operation of the Budd Inlet Treatment Plant. Additionally, if marine water were to overwhelm the treatment plant, it could kill the biological activity, potentially resulting in extended periods with little or no wastewater treatment.
Two lift stations, East Bay and Old Port 1, are currently located within the 100-year flood hazard areas. By the end of the century, three additional lift stations, Water Street, West Bay and East Bay Harbor, are predicted to be susceptible to flooding due to sea level rise. The Water Street and West Bay lift stations are the Utility's two largest lift stations. The Utility's Emergency Response Plan, Asset Management Program and Capital Facilities Plan need to account for these concerns in short and long term work efforts.
Other effects of climate change include changing weather patterns, including increasing precipitation intensities and durations. Increased precipitation intensities could overwhelm the capacities of some combined sewer pipes potentially leading to wastewater backing-up into the City's wastewater system and causing combined sewer overflows (flooding of streets, homes and businesses).
To protect the 450-acre downtown area from increasing sea levels, the City partnered with the Port of Olympia and LOTT to develop the Olympia Sea Level Rise Response Plan (SLR Plan). The SLR Plan provides comprehensive strategies for minimizing and preventing flooding to downtown Olympia, including the recommendation to incorporate sea level rise into other city planning documents. This Plan's climate change goal, objectives and strategies are consistent with recommendations contained in the SLR Plan. See Chapter 9 for additional information.
In 2018 Olympia entered into an interlocal agreement with the cities of Lacey and Tumwater and Thurston County to develop a regional climate mitigation plan. Phase I of the work has already been completed and resulted in the approval of a new communitywide emissions reduction goal by all project partners: To reduce communitywide emissions 45% below 2015 levels by 2030 and 85% below 2015 levels by 2050.
Phase II of the mitigation planning process will focus on developing and analyzing the strategies necessary to ensure that each partner jurisdiction hits the shared emissions targets. The Thurston Climate Mitigation Plan is expected to be completed in June 2020.
This Plan also addresses the Utility's actions intended to help slow down and reverse climate change. Efforts made by the Utility such as reducing energy use and promoting water conservation activities could assist the community in its efforts to mitigate climate change. For example, utility staff plan to explore the possibility of re-routing wastewater flow from the South Capitol neighborhood directly to the Budd Inlet Treatment Plant, bypassing the Water Street lift station. This project would alleviate surcharging in pipes on Capitol Way during rain events, as well as decrease energy use and the risk of overflow at the Water Street lift station, supporting objectives in the Climate Change goal.
8.5 Equitable and Predictable Rates and Fees
Creating predictability for customers and developers is important and can be difficult in a complex environment. The Plan will address the balance between ongoing utility needs and keeping rates as low as possible.
An important element of utility planning is predicting utility expenditures and maintaining a stable rate structure, including equitable rate structures for both commercial and residential customers. Ensuring a fair and equitable distribution of utility costs across the customer base is a City priority. A healthy and stable utility with predictable long-term revenues and expenses supports economic growth and developer investments in the community.
This Plan includes a detailed financial analysis (see Chapter 11) that evaluates current and potential future expenditures. Based on this analysis, necessary utility rates and general facility charges (GFCs) as assessed at the time of construction and connection to the City's wastewater system are recommended.
8.6 STEP Systems
STEP challenge topics include maintenance, including life cycle costs of major components; odor control and corrosion control.
Because STEP systems store solids in underground STEP tanks, wastewater from STEP tanks releases ammonia and hydrogen sulfide, which have an unpleasant "rotten egg" smell when exposed to the air in downstream gravity pipes. Additionally, when a STEP force main discharges into a maintenance hole or gravity sewer pipe, turbulent flows aerate the effluent, converting the hydrogen sulfide into sulfuric acid. The acid is highly corrosive to the concrete and metal in downstream pipes and maintenance holes. For example, within 20 years of initial STEP system installation, the downstream concrete gravity pipe in Lilly Road deteriorated to the point where it had to be replaced. Other pipes such as the one shown below on Boulevard Road have been lined. The corrosion in this pipe was bad enough to allow the gaskets at each joint to fall down.
While past capital projects have installed protective coatings in some discharge maintenance holes and downstream concrete pipes to address the corrosion problem, localized odor problems from hydrogen sulfide continue. As long as there are STEP systems in service, odor and corrosion challenges will occur.
Non-mechanical aerators and/or chemical filters may be necessary to neutralize odor as the wastewater is discharged into the gravity sewer pipes. In the southeast basin of Olympia, costly odor control equipment has been installed to address both odor and corrosion due to STEP effluent discharges into gravity sewer pipes. Odor complaints have also been received where STEP effluent is discharged to the gravity sewer system on Lilly Road and 14th Avenue NW. Odor in these locations have been managed by sealing the gravity sewer maintenance holes in the vicinity.
Figure 8.1 Example of a lined gravity sewer pipe
STEP systems costs more per connection for maintenance than the typical gravity sewer connection. However, other service cost disparities also exist, such as between a sewer connection located downtown and a remote connection for which wastewater is pumped through two or event three lift stations. To further understand the actual costs of providing service to STEP system customers, the Utility intends to update the 2005 STEP system business case evaluation.
8.7 Inflow and Infiltration
Inflow and Infiltration (I&I) from groundwater and stormwater can unnecessarily consume pipe and treatment plant capacity. To keep pipe capacities from being exceeded, priority areas for addressing I&I should be identified.
In areas with high groundwater, particularly in the wet season, groundwater (infiltration) and stormwater (inflow) can enter sewer pipes through joints, cracks and direct connections. Older pipes made of vitreous clay and concrete (mainly installed prior to 1960) are especially susceptible to infiltration. I&I can be substantial, effectively reducing the capacity of the pipes to convey wastewater. Sewer overflows and back-up can result. LOTT’s Budd Inlet Treatment Plant capacity is also adversely impacted.
There are a variety of I&I sources, as illustrated in Figure 8.1:
• Designed inflow from storm drains into combined sewer pipes, which carry both wastewater and stormwater.
• Planned (or illegally connected) inflow from storm drains (e.g., in a parking lot), roof or foundation drains, and other sources connected to a sewer pipe. In Olympia’s older neighborhoods many residential roof downspouts and/or basement sump pumps are piped directly into the wastewater system. These connections are not permitted under current regulations.
• Infiltration of groundwater into leaky sewer pipes and maintenance holes when the groundwater level is above the pipe or structure.
LOTT conducts a flow monitoring program initiated in 2003. In accordance with LOTT’s point source National Pollutant Discharge Elimination System (NPDES) Permit WA0037061, an I&I evaluation for all sub-basins within the LOTT system is performed each year. The purpose of the program is to ensure permit compliance, characterize flows within the collection system, identify areas of concern for I&I, and aid in the prioritization of rehabilitation projects to reduce I&I. The program is also intended to fulfill requirements of the Intergovernmental Contract for Inflow and Infiltration Management and New Capacity Planning, presented in Exhibit J to the LOTT Interlocal Cooperation Act Agreement for Wastewater Management (the agreement. The agreement required that the City of Olympia remove approximately 2.7 million gallons per day (MGD) of 10-year peak day I&I. Between 1996 and 2007, the City completed ten I&I reduction projects resulting in a reduction of more than 8.1 MGD of 10-year peak day I&I, fulfilling the City’s obligation. The Utility continues its efforts to identify and reduce I&I within the wastewater system.
Figure 8.2 Sources of Inflow and Infiltration
There are four main areas of Olympia that are susceptible to I&I:
• The westerly slopes of West Bay,
• The central business district, Capitol Campus and South Capitol Neighborhood,
• The plateau south of San Francisco Avenue and west of Puget Street in northeast Olympia, and
• The Ken Lake area.
Although there have been several projects to separate I&I from the wastewater system in these areas, I&I is still an ongoing challenge to Budd Inlet Treatment Plant capacity. In 2008, LOTT began offering a special funding program to encourage and support I&I removal projects conducted or sponsored by the partner jurisdictions. If a project is demonstrated to be “cost-effective” in removing flows to LOTT wastewater treatment facilities, it is eligible for funding consideration. I&I reduction projects are difficult for the following reasons:
• Cost of separating inflow from the wastewater system,
• Difficulty of separating inflow from sewer pipes on private property,
• Need to procure a new, permitted outfall for stormwater release, and
• Need to provide adequate treatment for separated stormwater flows.
So far, the emphasis has been on replacing leaky sewer pipes along the west slopes of West Bay, the west portion of the central business district, and the area immediately west of Ken Lake. Using the condition rating program, smaller sections of sewer pipe with I&I issues in many locations throughout the Sewer Service Area have been replaced or repaired.
8.8 Fats, Oils and Grease (FOG)
Significant utility staff time is spent on tasks associated with FOG, including educating customers on proper disposal methods, responding to wastewater system blockages and coordinating with LOTT. The Wastewater Utility’s current FOG cleaning program is focused on grease cleaning. To ensure it continues to be addressed, current staffing, anticipated staffing needs and potential opportunities to partner with the Storm and Surface Water Utility should be analyzed and identified.
Managing the public health risks of wastewater is a long-standing responsibility of the Utility. Often sewer overflows affect both public health and environmental quality. Sewer overflows have a variety of causes, including the buildups of FOG. The Utility has a proactive approach to prevent overflows caused by FOG. Operations and maintenance staff routinely clean pipes known to have problems with FOG. Staff closely monitor wet wells and pipe cleaning for the presence of FOG. When FOG is determined to be an issue, operations staff use CCTV equipment to identify the source, if possible. If the source is determined to be residential, staff educate residents and homeowners about the effects of dumping FOG into the sewer by sending postcards or letters. If the source is determined to be commercial establishment, most often a restaurant, utility staff coordinate closely with LOTT staff to eliminate improper disposal of FOG into the sewer system.